Go to http://www.rei.com and search for "walkie talkie". Even if the manufacturer says they're waterproof, you'll still want to keep 'em in a soft-shell waterproof case clipped to your PFD. A lot of people simply wear 'em around their neck... it's a matter of personal choice, but that feels like a ball & chain to me.

I use the ICOM VHF radio,its very good it floats, and if it gets wet its still good on sound quality. I like to use a marine VHF just in case you get into trouble you can call on help from coast guard or near by boats.